Which pranayamas are you practising? Is it kapalabhati and anulom-vilom?
I have done yoga for several years now but always focused much more on asana than pranayama. Of late I have not been doing yoga because I have found other ways of contemplation more appealing, and as far as physical health goes it was not really having a major impact.
As for Baba Ramdev, in my opinion he popularises some ancient wisdom, but there is also so much that is dubious about him. I suppose that a renewed flow of prana in the head would certainly help, that is something any yoga practitioner would know. From what I understand of yoga, I would recommend a far more meditative approach - slow, mindful, non-goal oriented, listening to the seven sheaths from the Taittiriya Upanishad - as compared to the mass yoga instructions that Baba Ramdev gives on TV. Living in India one tends to see people like Ramdev and a few others in a different light from those in the west. :)